Thatch (lawn)

In lawn care, thatch is a layer of organic matter that accumulates on a lawn around the base of the grass plants. Thatch is a combination of living and dead plant matter including crowns, stolons, rhizomes, and roots.

Turf cross-section showing thatch layer

Grass clippings do not generally contribute to thatch buildup as they can be easily broken down by soil microorganisms. Thatch is composed of about 25% lignin, a complex organic polymer that is highly resistant to decomposition. Thatch buildup can be caused by several factors:

• Certain grass species are especially prone to thatch production
• Acidic soils may not be able to support sufficient populations of decomposing microorganisms
• Certain fungicides can stimulate excessive root and rhizome growth
• Application of insecticides may reduce earthworm activity, leading to decreased bioturbation
• Over-application of nitrogen fertilizers can stimulate excess growth as well as contribute to soil acidity

A small amount of thatch may provide a beneficial insulating effect against fluctuations in temperature and moisture. However, excessive thatch can cause root problems and lawn mower difficulties. A dethatcher may be used to remove thatch from a lawn.

See also

• Plant litter – Dead plant material that has fallen to the ground

References

• Landschoot, Peter (January 9, 2023). Managing Thatch in Lawns (Report). Penn State College of Agricultural Sciences. p. 1. Retrieved January 30, 2024.

External links

• NDIS Lawn Mowing
• Professional Lawn Care